Severe Or Not To Severe

[fredmason]

I don't recall seeing any posts about the Severe setting on the GPZ.  I know there are some tough areas in the USA and even more so in Oz.

With the many varied operators on this forum I am curious to know when or if anyone has used SEVERE...if so, what were the results.

enquiring minds, etc

fred

[Northeast]

Yep, that is a good point. Northeast Vic and more so central Vic have plenty of hot rocks, hard red clay, etc and I've had switch to difficult frequently.  Was in difficult most of yesterday as it was just too noisy otherwise. 

But I find difficult just knocks out such a large percentage of hot rocks, hot ground that I've never needed severe. Have only ever dug 2 hot rocks whilst in difficult - and yes, I smashed them to make sure there was no yellow inside 

Maybe severe is used on salt lake beds, ironstone patches like I see on videos from Western Australia, etc. 

Would be interesting to hear if JP had to use it in testing on various grounds during the development phase of the Z.  

[fredmason]

thanks, guys, I hope others will contribute their experiences and opinions. 

some broad relevant questions;

why would one choose Severe

why would one not choose severe

Is severe an option that should never be chosen?

[Steve Herschbach]

Severe would be a last ditch attempt to get the GPZ to operate in ground where Normal or Difficult can't be made to work well. You would not choose to use it where it is not needed because it will impact performance on large deep nuggets. Severe is not an option that should never be chosen.

Personally, I have never encountered ground where I could not get Normal or Difficult to work for me.

 

[ozgold]

HI Fred

A while ago I use my zed on the beach here in Oz and the only setting I could use was Severe and sensitivity on 5 or less. In all the other settings it was just buzzing off its head and couldn't stabilise it in the salty dry sand.

I tried it in wet sand near the water, had sensitivity on 1 and got a few targets down deep. I couldn't recover them because the tide was coming in, the swell rising and I only had a square mouth brickies shovel ( not the right tool for the job )

I dug sum 2ft+ holes for coins & ring pulls further up the beach away from the water

cant help wondering what depth I would be digging in normal, general,19inch coil and max sensitivity

Just got my new 19inch yesterday, so this winter when beach is quiet I might give it a go

I also use severe to pinpoint when I've just about dug a target out of a hole, it give me better accuracy and direction

Cheers ozgold

[G.B.]

Fred

l have had the Zed since day one and detect in the Golden Triangle in Victoria.

The majority of the gold bearing ground in the golden triangle is basically highly variable highly mineralised ground. I have spent numerous hours using and learning about the Zed on the ground.

Averaging over that time approx 20 to 24 hrs a week. Up to now l have not encountered any ground that l have needed to utilise the Severe Ground Type Mode.

Basically what appears to me with the Zed is that ground that previous detectors struggled in the Zed relishes in.  Ground that the 4500 struggled to handle in enhance the Zed just eats up and spits out gold.

Take the time to learn the capabilities of the Zed and how to utilise the modes and settings and enjoy the experience.

[Lunk]

I've only needed to use the severe ground type setting once. It was on an old nugget patch where there is an outcrop of extremely hot volcanic rock. I knew there had to be nuggets in it, but even with the GPX 5000 the ground was way too noisy to discern targets. The severe setting on the Zed completely eradicated the ground response and the signals from the several small nuggets I proceeded to find were sharp and clear. 

[fredmason]

thanks for the responses, I will continue to learn and practice.

fred

[Jonathan Porter]

Hi all, Severe was developed for ground that is "Highly Saturable". Saturation means when you couple the coil to the ground it causes a swamping like target signal that drowns out everything else, this swamping effect is determined by the height of the coil from the ground. The only way to deal with Saturation (GPX detectors do this too) is to lift the coil above the saturation point or go to a mode that is less aggressive.  Generally the more saturable areas are also quite shallow so Severe was developed to allow the coil to be placed right on top of the ground in saturable soils without causing a large audio response, allowing shallow nuggets to stand out. 

Like all things there is a trade off, so Severe really pulls back on outright depth so should only ever be used in areas that are not deep. The GPZ 7000 is more prone to saturation than previous detectors in certain conditions so Severe was developed for that purpose. Quite often in WA Saturable soils are also salty so removing the Saturation signal can help a lot with identifying target responses. Severe is a variant of High Yield so has VERY good sensitivity to tiny gold.

Out of interest SteveH I helped develop Severe only a few miles south of where we were camped all those years ago.

JP

[fredmason]

Gosh, Jonathan that sure clarifies the issue. It also solves a small mystery for me. On my most recent trip I was getting weary of all the noise so I gave Severe a try,  even though  I knew I was reducing some sensitivity some way. After bit of blissful quiet I got a small nugget, then I got another. both were only 2-3 grains.

Now with all this great info I can make better decisions on which mode to use...

thank you ever so much!

fred